Calculation of the density of states and the thermal properties of polymer chains and stars on a lattice by the Monte Carlo method with the use of the Wang–Landau algorithm

The Monte Carlo method with the use of the Wang–Landau algorithm is applied to study the lattice models of free polymer chains and 6-arm polymer stars. The ratio of self-avoiding walks among semi-phantom walks for the chains of length $N\leq 300$ and the stars with the total number $N\leq 720$ of segments is determined. The distribution over the number of monomers' contacts for chains and stars with the number $N=30, 72, 120$ of segments is obtained. Based on this distribution, the temperature dependences are found for the internal energy, the heat capacity, and the entropy.